Jonny wrote:
> Hi,
>
> I am trying to write a C function which will dequote the string in a
> char * variable, and unescape any escaped quotes, so that, for example:

<snip examples>

Then go ahead and write it.
> Please can you help.

Yes, you've missed off a semi-colon on line 42.

In other words, if you want help with your code then post it together
with information about what specific problems you have with it. We are
not going to write your code for you.
--
Flash Gordon
Living in interesting times.
Although my email address says spam, it is real and I read it.

Do you want to copy the source string to a destination string
or replace everything in the source string? You can do both with
one function but be sure to think it through before.

Finding:
Just use strchr() to find quotes. If the number of backslashes
immediately preceding the quote is odd, you can 'replace' \" by ",
otherwise you replace " by nothing.
Note that you must not run to a position before the beginning
of the string, so use strrchr() to count backwards or take
appropriate precautions. Restart strchr() and your counting such
that you do not change already changed parts of the string.

Bring your best shot at it for us to see and we will help you
by pointing out problems and answering C questions.

Michael Mair <> wrote:
> This is quite enough. If you feel sure that you need to abort
> the program on an error, use
> if (*in != '\"') {
> assert(0 && "Unexpected character, expected \'\"\'");
> return;

I suspect that OP will want

exit( EXIT_FAILURE );

if he does in fact want to abort the program on an error in the
presence of _NDEBUG.
> }

--
Christopher Benson-Manica | I *should* know what I'm talking about - if I
ataru(at)cyberspace.org | don't, I need to know. Flames welcome.

Jonny <> writes:
> I am trying to write a C function which will dequote the string in a
> char * variable, and unescape any escaped quotes, so that, for example:
>
> "hello"
>
> would become:
>
> hello
>
> and:
>
> "\"hello\""
>
> would become:
>
> "hello"
>
> much in the same way as char *argv command-line arguments are treated
> when passed to function main.

You'll need to define the problem more precisely. The language
doesn't define any particular treatment of command-line arguments;
they're just made available to the program by some system-specific
means.

If you were on a Unix-like system, I'd say that you're probably trying
to duplicate what the shell does with command-line arguments before
invoking a program; for example

echo "\"hello\""

translates each \" to " and drops the outer " characters. This is
often very similar to the way string literals are treated within a C
program, but it's not identical. It can also vary from one shell to
another, and even within some shells depending on what options are
specified.

That's just one example of what you might be talking about. It's
likely to be different on other operating systems.

Once you've defined the problem, try implementing a solution in C. If
you have problems with it, post here again and we can try to help.

If this is a homework assignment, please say so.

--
Keith Thompson (The_Other_Keith) <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

I wrote:
> I am trying to write a C function which will dequote the string in a
> char * variable, and unescape any escaped quotes, so that, for example:
>
> "hello"
>
> would become:
>
> hello
>
> and:
>
> "\"hello\""
>
> would become:
>
> "hello"
>
> much in the same way as char *argv command-line arguments are treated
> when passed to function main.
>
> Please can you help.

Many thanks to you all for your help and advice. I wasn't sure where to
start, but you have given me enough information to have a go at this.

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